Method for affixing a magnetic resonance RF coil to a patient

The present application is a divisional application of U.S. application Ser. No. 12/120,856 filed May 15, 2008 (now abandoned).

1. Field of the Invention

The present invention concerns a method to affix an RF coil, in particular a local coil, on a patient for an examination with a magnetic resonance apparatus.

2. Description of the Prior Art

In a magnetic resonance examination, RF coils (in particular local coils) required to examine a patient are fastened on his body with the aid of straps or belts. Coils known as “under-coils” are placed on the horizontal board and have a rigid housing that is fashioned to accommodate the patient's weight. Coils known as “over-coils” are placed on the patient and are affixed on the body of the patient and on the horizontal board with the aid of fastening straps.

FIG. 2 shows such a magnetic resonance examination. A local coil LS is fastened or, affixed on the body of a patient P with the aid of a fastening strap BG. The local coil LS or its coil electronics module is electrically supplied via a relatively thick connection cable AK.

The connection cable AK is difficult to handle in combination with the local coil LS due to a (generally) large connection plug AS and interferes both during the examination and during the examination preparation.

Due to the necessity of connecting and disconnecting the connection plug AS before and after the examination, problems can occur in the reliability of the electrical connection via the connection plug AS.

In addition to the actual power supply of the coil electronics, the signal transfer from or to the local coil conductor also occurs via the connection cable AK.

At present concepts are under discussion to achieve the signal transmission wirelessly or with the use of optical fibers. Even with these concepts, however, it is still necessary to ensure the power supply to the coil electronics.

An object of the present invention is to provide a method to affix RF coils of a general type (but in particular local coils) on a patient in examinations with a magnetic resonance apparatus, which arrangement is improved with regard to handling.

This object is achieved in accordance with the invention by arrangement to affix RF coils on a patient in examinations with a magnetic resonance apparatus, wherein a horizontal board is used that serves to accommodate the patient for a magnetic resonance examination to be implemented.

Furthermore, at least one RF coil for the magnetic resonance examination is provided, the coil having coil electronics. The coil is affixed on the patient with the use of a fastening strap.

A connection or supply cable is an integrated part of the fastening strap via which the coil electronics are supplied with energy.

The necessity of the conventional, separate direction of the connection cable is foregone by the inventive combination of the fastening strap with the connection cable, such that the handling of the local coil with the connected supply or connection cable is made easier.

This is particularly advantageous in the use of multi-coil combinations given known as “body array” coils, and in the use of coils for angiography in the leg region, which are known as PAA coils.

In a preferred embodiment, fastening straps that can be fastened laterally at the horizontal board with a latching function (comparable to locking a seat belt in a vehicle) are used in the inventive arrangement.

Given the use of such fastening straps, electrical contracts are integrated within the mechanically designed latch connection.

Galvanically designed contacts can be used, or the electrical supply of the coils can ensue via inductive or capacitive coupling, comparable to charging devices that charge the batteries of an electrically operated toothbrush via coupling.

In another embodiment, the fastening strap contains capacitively or inductively designed signal couplers via which acquisition signals of the coils or local coils can be extracted. In this case a coupler counterpart is arranged on the top side of a coil housing, preferably below a fastening strap guide.

Due to low electrical requirements for the power supply, if such signals couplers are used it is possible to execute the connection plugs very simply. The operation of the connections is therefore further simplified.

In a preferred embodiment, the integrated connection cable is additionally used for data or measurement signal transfer of acquisition signals of the coils or local coils.

In a preferred development, data signals (that can be selected via filters in the individual coil housings) are then superimposed on the supply current.

FIGS. 1A and 1B show an embodiment of the inventive arrangement for use in a magnetic resonance examination.

FIGS. 1A and 1B show an embodiment of the incentive arrangement for use in a magnetic resonance examination.

FIG. 1C is an enlargement of a portion of FIG. 1B , schematically illustrating an embodiment wherein electrical power is supplied via galvanic electrical contacts.

FIG. 1D is an enlargement of a portion of FIG. 1B , schematically illustrating a further embodiment wherein power is supplied via inductive or capacitive couplers.

FIG. 2 illustrates the prior art described in the introduction in a magnetic resonance examination.

FIG. 1A shows the inventive arrangement for use in a magnetic resonance examination of a patient P.

A local coil LS 1 is fastened or affixed on the body of the patient P with the aid of a fastening strap BG 1 . The local coil LS 1 or its coil electronics is electrically supplied via a connection cable AK 1 .

The connection cable AK 1 is an integrated part of the fastening strap BG 1 or is connected with the fastening strap BG 1 for guidance.

For example, it can be arranged within a fastening strap (not shown here) designed with a tube shape or, as shown here, it is connected with the fastening strap with the aid of loops that are components of the fastening strap BG 1 . Both the fastening strap BG 1 and the connection cable AK 1 are thus directed together.

The electrical supply of the local coil LS 1 (more precisely of its coil electronic) here ensues via galvanically designed contacts with the use of a connection plug AS 1 .

FIG. 1B shows further details of the invention with reference to FIG. 1A .

The fastening strap BG 1 is laterally fastened on a horizontal board LB 1 with a latch connection RF 1 that has a latching function comparable to the catch of a safety belt in a vehicle.

The mechanically designed latch connection RF 1 moreover has additional electrical contacts K 1 ( FIG. 1C via which the power supply of the connection cable AK 1 can ensue via the horizontal board LB 1 .

The electrical supply of the local coil LS 1 here ensues via galvanically designed contacts with the use of the connection plug AS 1 .

As an alternative, the power supply of the coil electronics of the local coil LS 1 can ensue using inductive or capacitive couplers K 2 ( FIG. 1D ). These couplers are designed comparable to charging devices that charge batteries of an electrically operated toothbrush via coupling.

In a further embodiment, the fastening strap BG 1 additionally contains an integrated signal coupler KS 1 that is capacitively or inductively designed.

Acquisition signals of the local coil LS 1 are injected from the local coil LS 1 into the connection cable AK 1 via this signal coupler KS 1 .

A coupler counterpart KS 1 C for the signal coupler KS 1 is arranged on the top side of a coil housing CH of the local coil LS 1 .

The coupler counterpart is preferably arranged below a fastening strap guide such that the coupler counterpart is mechanically pressed onto the signal coupler KS 1 by the fastening strap BG 1 .

The transfer of the acquisition signals of the local coil LS 1 to the signal coupler KS 1 of the fastening strap BG 1 ensues via this coupler counterpart.

Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.